It is known additionally to activate the cleaning and disinfecting of medical or dental instruments in a bath by applying ultrasonic waves to the existing washing container. A device of this kind is disclosed, for example, in DE 33 24 939 A1 and EP 0 173 876 B1. In both known devices, ultrasonic transducers are arranged on the underside of the container base.
In a known device of this kind, in the case of a common washing container with a shape that is square or quadrilateral in the horizintal cross-section and with vertical side walls, an unsatisfactory utilization of the ultrasonic energy that is available and hence reduced efficiency of the ultrasonic cleaning can be expected. This is attributable to the fact that when the ultrasonic transducers are energized, ultrasonic waves come not only from the base of the container but also from the container side walls which are directly opposite one another and thus adversely affect the passage of the ultrasonic waves.